Henry xwilson c carpenter



H. W. CARPENTER.

SPARK PLUG.

APPLICATION FILED MAY I7. I9I.

1,329,320. Patented Jan. 27, 1920.

HENRY WILSON CARPENTER, OF KEY VJ E ST, FLORIDA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, T0 PHILIP IVILSON.

SPARK-PLUG.

Application nled May 17, 1918.

To all whom it may concern:

Be it known that I, l-Innnr IV. CARPEN- TER, a. citizen of the United States, residing at Key Illes@ in the countyv of Monroe and State of Florida, have invented new and useful Improvements in Spark-Plugs, of which the following is a speciiication.

present invention pertains to spark plugs and it contemplates the provision in a spark plug ot a simple and inexpensive device whereby the formation ot carbon deposits on the insulatingl casing surrounding the electrically energized conductor and the metallic housing or ground electrode of the spark plug will be prevented and short-circuiting or misfire will not occur.

In the use of spark plugs for internal combustion engines and more particularly such engines as are employed in aeroplanes, i-t is materially advantageous that carbon be prevented from forming on the insulating casing surrounding the conductor or in the chamber between this insulated conductor and housing; as such formation of Carbon deposits acts as a conductor between the wall or the housing` and the finger or the conductorl and prevents ignition of the gas.

Ity is to overcome this condition that I provide my novel device for keeping the chamber clean at all times.

With the foregoing in mind the invention will be fully understood Atrom the following` description and claims when the same are read in connection with the drawings, accompanying and forming part of this specification, in which:

Figure l, is a view partly in section showing a spark plug equipped with my novel derice.

Fig. 2, is a section showing, taken in the plane indicated by line A-A orn Fig. l.

Ifig. 3, is an elevation of my novel scavenging or cleaning washer.

'Eigl is a proper detail section of the plug. S Vlnilar numerals olf reference designate corresponding parts in all of the views of the drawings.

lily novel spark plug comprises the ordinary well known conductor 2, having a iinger 5, passing through its stem l0, and iurther having a finger 6 mounted on the metallic housing. The conductor is, more over, provided with insulating material-3,

Specification of Letters Patent.

Patented Jan. 27, 1920.

serial No. 235,079.

and at its end adjacent to the stem 10, the said insulating material has a collar 1l.

as is well known in the art, when the electric charge passes from the finger 5, of conductor 2, over the air gap, to the metallic linger 6, mounted on housing l, the gas will become ignited and pass into chambe1 9, whereupon the carbon and other deposits will be caused to collect on the stem l0, and inner wall of the housing l.

In order to immediatelyv clean or scavenge this stem 10, and inner wall, I provide my novel rider or washer T. The said washer is preferably formed of mineral wool, asbestos metal or mica and rests (in the preferred embodiment of the invention) reasonablv loose about the stem or core 10, allowing however for its free play upwardly and downwardly on stem l0.

The cleaning` of the stem and inside of the housing or plug shell occurs as an incident to the movement ot the washer which when the explosion in the combustion chamber ot the engine takes places is forced violer lj up toward the top of the chamber around the lower portion of the stem, by reason of the action of the compressed medium against the undersurface of the washer. By reason of the position of this washer across the entrance to the plug chamber the said entrance is obviously narrowly restricted to the space between the face of the opening in the washer and the contiguous surface of the core. The upward movement aforesaid sweeps the inner shell surface clear of any deposits of products of combustion. rlhe suction of the piston immediately following the compression and firing cycles producing reduction of pressure below the ring or washer, the tendency to equalization of pressures now forces the washer downwardly and the compressed air or gas being required to pass through the restricted space between the ring and stem, does so with considerable torce which naturally cleans the stein et any adhering particles, so that the zone oit possible short circuiting is at all times maintained thoroughly cleaned. In addition the washer has suicient body to produce a jarring which also assists in the displacement of any carbon particles.

In order to prevent the washer from being drawn out of the plug, I provide a metal boss or ring.

It has been demonstrated by actual test that a washer fitting loosely against the stem, has cleaned the same perfectly andthis is positive proof that said cleaning was brought about by the said washer confining the gas or air along the sides of the stem, as in such cases the washer never touched the stem. As has been brought out in the specification above, I wish to impress the fact that where the washer is formed of mineral wool, asbestos metal or mica, or any other like materials, it in itself, being driven violently Vupwardly and downwardly on the stem, because of its close contact with same cleans the stem and removes carbon deposits. On the other hand, when said Vwasher or rider is formed of material other than above designated, l depend upon the washer to form a confining space for gas or air in order to make the said gas or air in itself blow the carbon deposits from the stem and inside walls of the housing.

It will be gathered from the foregoing that my novel device is simple in construction and overcomes many objections heretofore present in spark plug cleaners; such for instance as springs which are employed to return the washer or rider to its original position.

Furthermore my device consists of no delicate parts such as are liable to quickly or easily, from any cause, become inoperative.

The Washer is preferably formed of the same material as the plug, thus allowing for uniform expansion and contraction and thereby preventing the washer from becoming stuck or firmly held in the chamber between the electrode and the housing.

Having described my invention, what I claim and desire to secure by Letters-Patent, is: Y

l. In a spark plug of the class described, the combination with a shell and a core therein, of a washer loosely mounted within the chamber surrounding the core, said washer narrowly restricting the entrance into the chamber and having sufficient of its surface exposed to the pressures in the combustion chamber of the engine to cause it to. be freely moved in the plug chamber under the actuation of pressure of explosion, said washer being free to move under the action of equalization of pressure in the plug chamber and the Vcombustion chamber following explosion. Y

2. ln a spark plug of the class described,

the combination with a shell and acore therein, of a washer of relatively heavy material mounted in the chamber between the core and shell and free to move upwardly along the core under actuation of the eX- plosion in the combustion chamber of the VYengine and downwardly in the opposite direction under the suction action of the engine piston, the outer peripheral surface of the washer wiping the inner wall of the shell during movements aforesaid, the edge of the opening of the washer being spaced from the core at all times to provide a restricted outlet for the gas confined above the washer during its said movement, whereby said gas will forcibly pass downwardly of the shell and remove deposits from the surface of the core.

3. A spark plug comprising a shell or body, a. core of non-conducting material mounted within said body and spaced from the wall thereof at its lower portion to provide a chamber, and means movably mounted. around the core in said chamber and con stituting compressing means operable upon explosion in the combustion chamber of the engine to compress the gas in the plug chamber, said compressing means being slightly spaced from the core to permit of the escape of the compressed gas to thereby remove deposits tending to adhere to the core.

4. A spark plug comprising a shell or body, a core of non-conducting material mounted within the body and spaced therefrom at its lower portion to provide a compression chamber, a ring -like member mounted within the chamber lightly contacting with the interior wall of the plug chamber, the ring-like member being slightly spaced from the core to provide a gas outlet and operable to compress the gas in the plug chamber above the member upon actuation incident to explosion in the combustion chamber of the engine, said compressed gas being permitted to escape subsequent to eX- plosion by the ring-like member along the core, thereby removing particles tending to adhere to the core.

ln testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

HENRY WILSON CARPENTER.

Witnesses ERNEST COTTON, P. P. VILsoN. 

